Abstract:
In most regions of Sri Lanka, rice is grown with intensive management under both irrigated and rainfed, low-land
puddled conditions. Apart from use of high yielding improved rice varieties recommended by the Department of
Agriculture, and timely management of pest and diseases; high rates of nitrogen (N), phosphorus and potassium
fertilizers are applied to attain high grain yield. Nitrogen is recommended to be applied in three splits i.e. basal
dressing at the time of planting and top dressings at tillering and panicle initiation to increase the N-use efficiency.
Farmers apply excess amounts of N because of the availability of subsidised N fertilizers. Based on the latest research
findings and to improve the efficiency and effectiveness of N application, the Department of Agriculture recently
recommended an application of four splits of N without the application of basal dressing. Therefore, in this simulation
modelling study yield response of a widely grown Sri Lankan rice variety Bg 300 under two N application
recommendations; with and without the addition of basal dressing was analyzed using the simulation model APSIM.
Results revealed that yield obtained through the new recommendation was similar to that of the previous
recommendation.
